Professor P.J. Hore

Research

My group studies radical pairs – ubiquitous short-lived reaction intermediates whose chemistry is controlled to a large extent by electron and nuclear spins. Their defining characteristics are spin-selective reactivity and long-lived spin-coherences which result in reaction rates and product yields that are sensitive to magnetic interactions orders of magnitude weaker than the thermal energy per molecule, kT. Thus, manifestly quantum effects of weak magnetic fields on chemical reactions occur under conditions where the corresponding classical effects would be entirely negligible.

Our research exploits the unique properties of radical pairs using a range of experimental and theoretical approaches. For example:

• We are testing the hypothesis that birds rely on radical pair reactions in the retina to detect the direction of the Earth’s magnetic field as a compass for use during migration.

• We develop and apply NMR techniques for studying protein folding in real time using the nuclear spin polarization effects that arise in photo-induced radical pair reactions.

• We use weak static and time-dependent magnetic interactions to probe and control the reactions of radical pairs that are too short-lived to be detectable by more conventional magnetic resonance methods.

• We are applying ideas from quantum measurement theory to find the correct way to describe spin-selective radical pair reactivity.

• We have developed and are using a variety of approaches to accelerate Liouville-space simulations of the large densely coupled spin systems encountered in EPR spectroscopy and Spin Chemistry.